Patent application number | Description | Published |
20080304591 | Apparatus and Method for Estimating Channel in Communication System Supporting Ofdm/Ofdma - Disclosed are an apparatus and a method for estimating a channel in a base station when using a Partial Usage of Sub-Channels (PUSC) mode in an uplink channel of the communication system supporting Orthogonal Frequency Division Multiplexing/Orthogonal Frequency Division Multiple Access (OFDM/OFDMA). For this, the channel estimation apparatus used in the communication system supporting the OFDM/OFDMA comprises a phase estimation/compensation unit estimating and compensating phase change of a channel by using pilots included in signals input by sub-channel; and a channel estimation unit estimating the channel by averaging the pilots of the signals of which the phase is compensated. | 12-11-2008 |
20090003423 | Frequency Offset Estimation Apparatus and Method in Wireless Communication System - The present invention relates to an apparatus and method for estimating a frequency offset in a wireless telecommunication system. The present invention does not estimate an initial frequency offset using a preamble which is the initial symbol of a frame upon estimation of the frequency offset in the wireless telecommunication system, but estimates a frequency offset using correlation of a cyclic prefix (CP) existing in each symbol, thereby eliminating a need to reproduce information about separate preamble signals and preamble signals, and easily estimating a frequency offset using only input signals. | 01-01-2009 |
20090010348 | Decoding Apparatus and Decoding Method - Provided are a decoding apparatus, a decoding method and a receiving apparatus for decoding in a system supporting an OFDM/OFDMA scheme. The decoding method includes the steps of: receiving phase-modulated signal; performing subcarrier demodulation on the received signal and generating correlation metrics; generating decoding metrics using the correlation metrics; and determining a payload using the largest metric of the decoding metrics and at least one of an average metric and the second largest metric of the decoding metrics. The decoding apparatus includes: a receiving buffer for buffering received phase-modulated signal; a likelihood metric generator for generating decoding metrics corresponding to likelihoods of the received signal buffered in the receiving buffer being determined as respective potential payload values; a mean calculator for calculating an average metric; and a payload determiner for determining a payload using the largest metric of the decoding metrics and at least one of an average metric and the second largest metric of the decoding metrics. | 01-08-2009 |
20090046799 | DECODER AND DECODING METHOD SUPPORTING OFDM/OFDMA - Provided are an apparatus and method for efficiently decoding signals input through a plurality of antennas in a system supporting an Orthogonal Frequency Division Multiplexing (OFDM)/Orthogonal Frequency Division Multiple Access (OFDMA) scheme. A method for decoding signals received via at least two paths through a plurality of antennas in a system supporting an 0FDM/0FDMA scheme, the method comprising the steps of: measuring power of a signal received via each path; generating correlation metrics by calculating inner products of basis vector sets or multiplying the basis vector sets in units of tiles or bins of the signal; generating decoding metrics based on the measured power of each path and the correlation metrics; and determining a payload on the basis of the decoding metrics. An apparatus for decoding signals received via at least two paths through a plurality of antennas in a system supporting an OFDM/OFDMA scheme, the apparatus comprising: a signal power measuring means for measuring power of a signal received via each path; a demodulation/decoding means for generating correlation metrics corresponding to likelihood of potential payload values of a signal received via each path; and a maximum ratio combining (MRC)/determination means for determining a payload based on the measured power of each path and the correlation metrics. | 02-19-2009 |
20090052563 | DECODING APPARATUS AND DECODING METHOD - Provided are a decoding apparatus and method for a system supporting an Orthogonal Frequency Division Multiple Access (OFDMA) scheme, the apparatus and method compensating received signals according to a wireless channel estimation result and thereby simply performing decoding by a coherent method. The decoding method includes the steps of: receiving a Quadrature phase shift keying (QPSK) modulated signal; compensating the received signals by applying a result of channel estimation based on pilot signals to the received signals; performing subcarrier demodulation to generate correlation metrics on the basis of the compensated received signals; and performing decoding using a decoding metric derived from the correlation metrics. The decoding apparatus and method compensate a received wireless signal according to a channel estimation result of a wireless channel through which a signal is transmitted, thereby performing decoding by a coherent method having a simple structure. | 02-26-2009 |
20090052596 | DECODER AND DECODING METHOD - Provided are a decoding apparatus and method for a system supporting an Orthogonal Frequency Division Multiplexing (OFDM)/Orthogonal Frequency Division Multiple Access (OFDMA) scheme, the apparatus and method capable of simply performing decoding by a non-coherent method. The decoding method includes the steps or receiving quadrature phase shift keying (QPSK) modulated signal; performing subcarrier demodulation whereby correlation metrics are generated on the basis of the received signal; and performing decoding using a decoding metric derived from the correlation metrics. The correlation metrics are obtained by multiplying tile, bin or zone of received signal by sets of basis vectors. The decoding apparatus includes: a receiving buffer for buffering received QPSK modulated signal; a correlation metric generator for generating correlation metrics on the basis of the received signal buffered in the receiving buffer; and a decoding processor for performing decoding using a decoding metric derived from the correlation metrics. | 02-26-2009 |
20090232080 | FREQUENCY REUSING METHOD IN WIRELESS COMMUNICATION SYSTEM AND RADIO ACCESS STATION SYSTEM FOR THE SAME - The present invention relates to a wireless communication system, and more particularly, to a frequency reusing method for efficiently transmitting traffics in a radio access station system. A frequency reusing method in a wireless communication system including a coverage region, which has first, second and third regions comprises (a) transmitting traffics by assigning a total frequency band, which includes different three sub-frequency bands, to the first, second and third regions during a first interval; and (b) transmitting the traffics by respectively assigning the different three sub-frequency bands to the first, second and third regions during a second interval. | 09-17-2009 |
20090252028 | APPARATUS AND METHOD FOR CONTROLLING RANGING OF MOBILE TERMINALS IN WIRELESS COMMUNICATION SYSTEM - Disclosed are an apparatus and a method for controlling ranging in a wireless communication system. The apparatus according to the present invention comprises a Radio Frequency (RF) module converting RF band signals received via antenna to low-frequency band signal; a Fast Fourier Transform (FFT) module converting the low-frequency band signal of time-domain to frequency-domain signal; a derandomizer performing derandomizing the frequency-domain signals by using a random sequence being transmitted by the terminals; a depermutation module combining the frequency-domain signals output from the derandomizer by unit of burst and outputting the combined signal; and a ranging controller controlling periodic ranging of the terminal corresponding to the respective bursts by estimating phase change in the frequency-domain signals of burst unit. | 10-08-2009 |
20100111005 | APPARATUS AND METHOD FOR TRANSMITTING UPLINK SIGNALS IN A WIRELESS COMMUNICATION SYSTEM - The present invention relates to an apparatus and method for transmitting uplink signals in a wireless telecommunication system. According to the present invention, it is characterized that at least one uplink signal is allocated to other symbol duration for time dispersion in case a plurality of uplink signals are scheduled to be allocated to the same symbol duration of the uplink frame that the terminal transmits to the base station. Accordingly, the terminal can enhance the power spectral density of the uplink signal and the error rate can be reduced. | 05-06-2010 |
20110002286 | METHOD AND APPARATUS FOR ALLOCATING DATA BURST - A method and apparatus for allocating a data burst is disclosed, which is capable of differently setting a start symbol offset, at which an allocation of data burst is started, by each sector when allocating the data burst into a downlink sub-frame for each of neighboring sectors, wherein the method is comprised of dividing a data region of a downlink sub-frame for each of neighboring sectors into a plurality of segment regions, and allocating each of the segment regions into the respective sectors without being overlapped; and allocating downlink data bursts for the respective sectors, wherein the allocation of downlink data bursts is sequentially started from the segment region allocated for each sector. | 01-06-2011 |
20110003605 | METHOD AND APPARATUS FOR ALLOCATING DOWNLINK POWER IN WIRELESS COMMUNICATION SYSTEM - A method and apparatus of allocating downlink power in a radio access station system are disclosed. The method of allocating transmission power to a plurality of terminals in a radio access station system according to the present invention includes (A-1) calculating an allocation power for the respective terminals based on downlink quality information of the respective terminals; (A-2) calculating a minimum requirement power for the respective terminals based on the downlink quality information; and (A-3) allocating the transmission power by distributing part of excess power of a first terminal group having the allocation power higher than the minimum requirement power to the second terminal group having the allocation power lower than the minimum requirement power, and the part of excess power is a sum of insufficient power of the second terminal group. As a result, the loss of the quantity of service transmission of the radio access station is reduced and service areas can be expanded. | 01-06-2011 |
20110026482 | METHOD AND APPARATUS FOR PILOT SIGNAL TRANSMISSION - A method and apparatus for pilot signal transmission is disclosed, which is capable of improving efficiency in a wireless communication system, the method comprising transmitting an uplink transmission frame for a first sector or cell by a mobile station through the use of basic pilot pattern in a resource block and transmitting an uplink transmission frame for a second sector or cell by the mobile station through the use of shift pilot pattern which is not overlapped with the basic pilot pattern in the resource block. | 02-03-2011 |
20110134859 | FRAME TRANSMISSION METHOD USING PRECODING FOR SUPPORTING MU-MIMO, AND BASE STATION SUPPORTING THE FRAME TRANSMISSION METHOD - Disclosed is a frame transmission method using precoding for supporting MU-MIMO, which facilitates to reduce overhead of a downlink frame in a wireless communication system of FDD method, and a base station supporting that method. The frame transmission method comprises calculating a precoding matrix of a present frame based on channel state information (CSI) of each mobile station and a precoding matrix of a prior frame; precoding a dedicated pilot and downlink data to be transmitted to the mobile station by the use of precoding matrix of the present frame; and transmitting a downlink frame including the precoded dedicated pilot and precoded downlink data to the corresponding mobile station. | 06-09-2011 |
20140103332 | THIN FILM TRANSISTOR DISPLAY PANEL - A thin film transistor display panel a includes a transparent substrate; a gate electrode positioned on the substrate; a gate insulating layer positioned on the gate electrode; a semiconductor layer positioned on the gate insulating layer and including a channel region; a source electrode and a drain electrode positioned on the semiconductor layer and facing each other; and a passivation layer configured to cover the source electrode, the drain electrode, and the semiconductor layer, wherein the semiconductor layer includes a relatively thick first portion between the source electrode and the gate electrode and a relatively thinner second portion between the drain electrode and the gate electrode overlap, the relatively thick first portion being sufficiently thick to substantially reduce a charge trapping phenomenon that may otherwise occur at a gate electrode to gate dielectric interface if the first portion were as thin as the second portion. | 04-17-2014 |
20140198774 | APPARATUS AND METHOD FOR CONTROLLING RANGING OF MOBILE TERMINALS IN WIRELESS COMMUNICATION SYSTEM - Disclosed are an apparatus and a method for controlling ranging in a wireless communication system. The apparatus according to the present invention comprises a Radio Frequency (RF) module converting RF band signals received via antenna to low-frequency band signal; a Fast Fourier transform (FFT) module converting the low-frequency band signal of time-domain to frequency-domain signal; a derandomizer performing derandomizing the frequency-domain signals by using a random sequence being transmitted by the terminals; a depermutation module combining the frequency-domain signals output from the derandomizer by unit of burst and outputting the combined signal; and a ranging controller controlling periodic ranging of the terminal corresponding to the respective bursts by estimating phase change in the frequency-domain signals of burst unit. | 07-17-2014 |